About This Project

Natural rock weathering sequesters CO2 for thousands of years and provides essential nutrients for plant growth. In nature, however, this process is too slow to significantly mitigate climate change and restore soil fertility. With enhanced weathering (EW) we accelerate this process by spreading finely ground rock powders on agricultural lands. We employ this in the place with the highest potential for weathering and food security: the tropics.

Ask the Scientists

What is the context of this research?

Enhanced weathering (EW) is among the most promising Negative Emissions Technologies (NET) and has significant potential to improve soil health and food security. Although the overall potential is highest in the tropics, EW experiments have hithertho focused on the global North. Together with our unique network of farmers, scientists, mines and agronomists, we thus establish the first EW experiments in the tropics to catalyze the development of this frontier technology. The overall carbon drawdown efficiency depends upon various factors like sourcing of the rock powder or distance from mine to the field, which will all be optimized for our field trials.

What is the significance of this project?

EW in the tropics has the potential to tackle some of the biggest planetary challenges: climate change, soil health, and food security. However, high CO2 drawdown potential through EW is still theoretical. We desperately need field experiments to outline the actual CO2 capture capabilities of these processes.

If scaled accordingly, EW is one of the few negative emission technologies that could sequester CO2 in the Gt scale until 2050.

The tropics have by far the biggest potential, as the factors that accelerate EW are highest: temperature, rainfall, and very acidic soils. Furthermore, the tropics show the best agricultural results for rock powders regarding soil health and yield increases.

What are the goals of the project?

Exactly quantifying how much CO2 is sequestered by EW is still the biggest uncertainty. Oftentimes only some parameters like soil nutrients have been analyzed. These results likely underestimate real CO2 sequestration. To comprehensively quantify sequestration rates of EW we analyse on a weekly basis the soil water and on a monthly basis soil physiochemical data, and include regular analysis of plant yield and plant nutrient content (3-5 cuts per season). We already secured the field site with an oxisol (highly weathered soil type that is most suitable for EW), agronomically certified basalt rock powders (>800t), and will additionaly measure CO2 on and in the soil once the EGM5 arrives in Brazil.